Wear patterns on correct M1

[RCS]

The grooved rear handguard band was gone by July-August 1942, early gas trap period rifles had the grooved rear handguard band with the drawing number inside (two variations). you need the correct tool to remove the band. The follower rod is the short fork which would not be found in a rifle with your serial range, the op rod catch could be
Winchester. If you can provide more photos of the internal parts, they might be able to be identified. As jmoore stated the stock has overhang on the rear of the receiver. The rear sight cover might not be SA